Oscillator



B. J. LAZAN Sept. 2'], 1949.

OSCILLATOR 4 Sheets-Sheet 1 Filed July 13, 1945 INVENTOR Filed July 13,19 45 B. J. LAZAN OSCILLATOR 4 Sheets-Sheet 2 INVENTOR flea 2w):(11.4240

N A z A L Im a Sept. 27, 149.

R o T A L L I c S 0 4 Sheets-Sheet 3 Filed July 13, 1945 IN V E NTO Rfizzy bark 1/ 42m ATTORNEY N A Z A L l B Sept. 27,1949.

R O T A L L I C S 0 4 Sheets-Sheet 4 Filed July 13, 1945 Patented Sept.27,1949

OFFlCE OSCILLATOR Benjamin J. Lazan, Greenwich, Conn. Application July13, 1945, Serial No. 604,781

Claims.

This invention relates generally to materials testing apparatus and moreparticularly to oscillators for producing a vibrating force which isnormally used for loading structures or specimens under test.

It is an object of my invention to provide an oscillator having improvedmeans for adjusting the degree of eccentricity of rotatable weightswhich produce the vibrating force, the magnitude of the force being inproportion to the degree of eccentricity. Another object in this respectis to provide an improved mechanism for adjusting the eccentric weightsin such a manner that the adjusting forces are so related to each otheras to insure not only ease in varying the eccentricity, but also inreducing to a minimum any wear and tear on the moving parts duringoperation.

A further object is to provide an improved oscillator in which therotating eccentric weights and driving mechanism together with theadjusting elements are so arranged in a cooperative relation as toproduce a highly compact device and yet have'the parts easily assembledand accessible. In one particular aspect of my invention I accomplishthe foregoing and certain other objects by mounting the major portion ofthe operating structure and adjusting mechanism about a common axiswhereby the oscillator is of relatively small transverse dimensions andat the same time have the parts so related as to obtain a reasonabledegree of accessibility without in any way sacrificing ease andprecision of adjustment of the eccentric weights.

Other objects and advantages will be more apparent to those skilled inthe art from the following description of the accompanying drawings inwhich:

Fig 1 is a longitudinal vertical section taken substantially on the linel-l of Fig. 2;

Fig. 2 is a section taken on line 22 of Fig. 1, parts being shown inelevation for clarity;

Fig. 3 is an enlarged perspective of an eccentric weight and mechanismfor adjusting the eccentricity, parts of which are broken away to showdetails of construction and the weight being shown in its lower positionfor purposes of clarity whereas the weights are shown in their upperposition in Fig. 1;

Fig. 4 is a perspective of one of the combined drive sleeves and guidesfor the eccentric weights;

Fig. 5 is an elevational view of the shaft racks for adjusting aplurality of eccentric weights;

2 for supporting the eccentric weights by the adj usting racks;

Fig. 7 is a bottom plan view looking upwardly at the underside of Fig.6; and

Fig. 8 is'a transverse section taken-on line 8-8 of Fig. 1.

In the specific embodiment of the invention disclosed herein forpurposes of illustration, I provide a box-like casing I whose bottomside 2 is open to allow assembling of the rotatable force producingmechanism while a base plate 3 normally supports the casing. The forceproducing mechanism comprises a plurality of coaxial eccentric weightsspecifically shown as three in number 4, 5 and 6, respectively supportedon drive sleeves l, 8 and 9. These sleeves are journalled in ballbearings supported in the casing end wall Ill andalso in transversebearing supports I l bolted to or otherwise formed as part of thecasing. Suitable downwardly removable bearingcaps [2 are held on thebearing supports by bolts l3.

It will be understood that the weights 4 and 1 6 are driven together asa unit in one direction Fig. 6 is a side view of a modified arrangementand the weight 5 is simultaneously driven at the same angular speed asweights 4 and 6 but in the opposite direction. The horizontal forcecomponents of the three weights are arranged to cancel out each otherwhile the vertical components of all weights are additive both upwardlyand downwardly. This is accomplished in the well-known manner of havingthe two sets of weights so angularly driven that during rotation theweights 4 and Swill be on one horizontal side of the axis of rotationwhile the weight 5 is on the diametric opposite side. This leaves onlyvertical force components by reason of weights 4 and 8 moving toward avertical plane from one sidev of the axis while weight 5 is movingtoward the same point in the vertical plane from the opposite side ofthe axis, this movement taking place once at the lower side of the axisof rotation and again at the upper side thereof during each revolutionthereby producing a vertical vibrating force.

p In my improved arrangement I adjust the radial position of all weightsin order to change the centrifugal force produced by the weights andaccordingly vary the vibrating force capacity of the apparatus. To dothis I have provided a plurality of coaxial sleeves 1,3 and 9 ofgenerally similar construction and hence'the description of one willsufi'ice for all except where otherwise noted. Foreonvenience, thesleeve 1 3 is shown partially isolated in Fig. 4 and. assembled inFig. 1. It comprises cylindrical bearing portions M at each end with an.intermediate square portion I5 in which a pair of vertical guidewayslots I 6 are formed of sufiicient depth so as to intersect asubstantial portion of a bore H extending through the entire sleevelength. Disposed in said bore is an axially shiftable hollow rack shaftl8 having rack teeth I9 and cut on fiatted surfaces o each side of; the,shaft. The arrangement of Fig. 4a, in turn, supports the eccentricweight 4 in the manner shown in Fig. 3.

The lengths of the individual sleeves are determined in accordance withthe width of the different weights.

The weights may be formed in various man-1 ners one of which as shown inFig. 3 comprises.

two main weight segments 23 and 24 held apart by a smaller centralsegment 25 all of which are bolted as by screws 26. The central segment25 is; provided with a pair ofverticalslots one of which is shown at 21for receiving: a pair of: transversely extending combined weightsupporting and rack arms 28- and; 29. These arms are 9- and 20, Figs. 3.and, 4, of the axially shiftable rack shaft, [8. whereby it is seen thatupon axial movement of, this shaft the inclined rack teeth will causethe rack arms. and weights to-be moved: radially outward or inward, as.the. case may be, and thereby adjust. the, centrifugal force. pro-.duced. by the eccentric weights.

To drive the sleeves I and 9 together in thesame direction while drivingsleeve 8, in the opposite direction, I have provided as. shown in- Fig.1 a, shaft 35. which is keyed as at 36. to. shaft, 18,. This shaftterminates at. its. right end in an enlarged cylindrical portion 31having; opposite fiatted sides on which rack teeth 38. are formed tomesh with therach arms of weight 6. in iden-. tically the same manneras, that. shown in Figs. 3, and 4 exceptthat the-rack teeth 38 areformed; on a solid member. 5 1Gb as 31. instead oi a hollow rack shaftl8. The sleeves! and 8 are driven directly by bevel gears 33 and whilea, bevel, pinion 4 sup o d n a. suit b y iournall d shaft 42 is drivenfrom any suitable electric motor 43. or o her p w sour e. He ce. wei ht,5 is mtatably driven in one direction and weight 4 rotatably driven inthe opposite direction, the driving force being transmitted, Fig. 4,through guideway l6: of sleeve T and thence to rack shaft i8 and key 36,Fig. 1, to shaft 35 which causes rotation thereof with consequentrotation of weight 6 through racks. 38' and rack arms. 28 and 29'.

To radially adjust the weights, it will be'first understood that a racksleeve 45, Fig. 1, corresponding broadly to rack sleeve, [8, isinterposed between the latter sleeve and the left shoulder of enlargedshaft portion 31. Suitable thrust bearings 46 and 41 are disposed ateach end ofsleeve 45. Axial shifting of shaft 35 in either of oppositedirections will cause the racks 38, and; similar racks on sleeves l8 and45' to. adjust simultaneouslythe. radial; nQ ition of a l weights.

To effect such axial adjustment of shaft 35 the enlarged portion 31thereof is provided with a yoke 49 having a suitable thrust bearing 50.A plurality of symmetrically arranged screws 5| are threaded in yoke 49and are journalled at their opposite ends in one of the journal supportsI2 and in the end wall of casing I. To rotate the screws 5| and therebymove yoke 49 and. shaft 35 axially, each screw is provided with awor-mwheel 52 commonly engaged by aworm 53. This worm may, if desired;be rotated in either of opposite directions by an electric motor 54 inaccordance with the magnitude of vibrating force desired.

The weights may be additionally supported as shown in Fig; 6 by screws56 extending from the outer weight segments 23 and 24 to an overhangingtype of cross member 51 which takes the place of member 30 in Fig. 3.Suitable dowels 58 may be employed between member 51 and the weightsupporting rack arms.

From the foregoing disclosure, it is seen that I have provided an.oscillator having a high de gree of transverse compactnessflexibility ofoperation and control, together with rugg dness as well as many otherqualities and characteristics de irabl n a device of t inath d v e be.-ing relatively narrow in its, transverse dimensions, by reason of havingthe oppositely rotating eccentric weights all mounted about a singlecommon a s o rot i wh l other o th advanta es a s o a e i n and d.--justing forces largely self-contained within cerain. as g eleme sthereby din t e v necessity of many complications heretofore present inoscillators of other types. It is to. be noted that the weights are ofdifferent sizes, proportioned in accordance with the axial distancebetween each other so as to eliminate any torsional moments about atransverse plane.

The difference, in axial spacing of the weights is caused by the bevel;gear drive interposed; between two of the weights. To obtain axial com;-pactness when the third weight is added but at the same time avoidtorsional moments I arrange the masses as described.

It will of course be understood that various changes in details ofconstruction and arrangement of parts may be made by those skilled inthe art without departing from the spirit of the invention as set forthin the appended claims.

I claim:

1. An oscillator comprising, in combination, a pluralityof eccentricweights, means for rotating said weights opposite directions from eachother about a common axis and in such angular relation to each other asto produce a resultantvibratory force in a predetermined direction,means for supporting said weights for movement radially of said commonaxis, and means movable axially alongsaid common axis for radiallyadjusting said weights so as to vary the magnitude of the resultantforce. I

2. Anoscillatorcomprising, in combination, a plurality of eccentricweights, means for rotating said weights in opposite directions fromeach other about a common axis and in such angular relation to eachother as to produce a resultant vibratory force in a predetermineddirection, and means movable along said common axis for adjusting saidweights so as to vary the magnitude of the resultant force, said weightscomprising at leasttwo weights rotating together in one direction andspaced; axially along the axis of rotation and another we ght dis se beween said xi l y spaced weights and rotating in the opposite direction,the axially spaced weights being of different sizes and each of suchweights being individually smaller than the intermediate weight, andsaid intermediate weight being axially spaced from one of the smallerweights a greater distance than from the other smaller weight, anddriving mechanism for said weights being disposed within the space thathas the greatest distance between the larger weight and one of thesmaller weights.

3. An oscillator comprising, in combination, a plurality of weightscertain of which rotate in one direction and others in an oppositedirection along a common axis and in such angular relation to each otheras to produce a resultant vibratory force in a desired direction, meansfor supporting said weights for movement radially of said axis and meansmovable along said common axis for radially adjusting at least one ofsaid weights to vary the magnitude of the resultant vibratory force.

4. An oscillator comprising, in combination, a plurality of eccentricweights rotatable in directions opposite to each other about a commonaxis, individual sleeves arranged coaXially of each other and havingtransverse guideways intersecting their interiors, journals for saidsleeves, transverse rack arms connected to said weights for supportingthe same and radially slidable in said guideways, and rack gearsdisposed within said sleeves for engagement with the rack arms andaxially movable so as to efiect radial adjustment of the rack arms andweights attached thereto. 5. An oscillator comprising, in combination, aplurality of eccentric weights rotatable in directions opposite to eachother about a common axis, individual sleeves arranged coaxially of eachother and having transverse guideways intersecting their interiors,journals for said sleeves, transverse rack arms connected to saidweights for supporting the same and radially slidable in said guideways,rack gears disposed within said sleeves for engagement with the rackarms and axially movable so as to effect radial adjustment of the rackarms weights attached thereto, and means for rotatably driving saidaxially movable racks whereby rotation is imparted from at least one ofthe axially movable racks through its cooperating rack to the weightattached thereto.

BENJAMIN J. LAZAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date Dempsey et a1 Dec. 29, 1936 J ohnstoneDec. 26, 1944 Number

